Triggers or buttons are commonly used on electronic devices. For instance, triggers are employed on mobile computing terminals, bar code scanners, cellular phones, portable digital assistants (PDAs), etc. The trigger is used to initiate certain functions on the device. For instance, the trigger could activate a connection for telephonic communication, activate a data transfer function, or be used to navigate through menu options on a display. In another example, the trigger may activate a data capture engine, such as a module to capture bar code information, wherein the module may include a laser based bar code scanner or an imager for reading a barcode.
Various electro-optical systems have been developed for reading optical indicia, such as barcodes. A barcode is a coded pattern of graphical indicia comprised of a series of bars and spaces of varying widths, the bars and spaces having differing light reflecting characteristics. Systems that read and decode barcodes employing a laser are typically referred to as laser-based barcode readers or barcode scanners. In the case of operating a data capture device such as a bar code scanner, activating a trigger typically would notify a processor to turn on a laser and detector engine, operate a mirror to scan the laser beam over an area, operate the detector engine to receive any light reflections of the laser beam, and decode the reflections to determine if there is any barcode information within the reflections.
Systems that read and decode barcodes employing Charge Coupled Device (CCD) or Complementary Metal Oxide Semiconductor (CMOS)-based imaging systems are typically referred to as imaging-based barcode readers or barcode scanners. Imaging systems include CCD arrays, CMOS arrays, or other imaging pixel arrays having a plurality of photosensitive elements or pixels. In the case of a data capture device such as an imager, activating a trigger typically would notify a processor to turn on an image detector engine, illuminate an area such that light reflected from a target image, e.g., a target barcode, is focused through a lens of the imaging system onto the pixel array. An analog-to-digital converter digitizes output signals from the pixels of the pixel array to capture an image frame of the area. Decoding circuitry of an imaging engine analyzes the digitized signals and attempts to determine if there is any barcode information within the image to decode.
In typical operation, once a decoding sequence has been initiated, an image acquisition process is started, during which an aiming pattern is projected onto the desired barcode during the scanning process. This typically involves an operator engaging a trigger located on the scanner, which enables the aiming pattern to be projected while simultaneously initiating the decoding process of the image or barcode to be scanned. The aiming pattern is then turned off and an illumination is projected through a window of the scanner at a target barcode, of which an image is reflected back through the window at a lens onto an array of photo sensors or pixels located within the CCD or CMOS imager. The pixels of the pixel array are read, generating an analog signal that is sent from the imager engine to an analog to digital converter, which then sends a digital signal to a decoder where it becomes synthesized by the decoder's internal circuitry and analyzed to decode the barcode information. The decode session is terminated with the decoded information being sent to an output port and/or display for the operator's attention. However, in either of an imager or laser-based systems, there is a power expenditure involved in illumination and a certain time latency before decoding can be successful due to the many operating steps.
Accordingly, there is a need for a technique to alleviate the above issues in triggering electronics, power consumption, and operational latency of triggered electronics such as a data capture engine.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.